The ingestion of toxic substances has historically been and continues to be a significant problem. While efforts in recent years to mitigate ingestion of toxic substances have arisen, such as conspicuous labeling, tamper-proof sealing, and limiting the number of tablets in bottles of children's medicines, a significant numbers of poisoning incidents continue to occur. Moreover, an overwhelming percentage of these incidents occur in the residence, and the majority of the victims tend to be young children.
In the emergency treatment of poisoning, unless a specific antidote exists, which is uncommon, the effort centers on two main objectives: (i) general support and stabilization and (ii) decontamination. As decontamination and treatment must begin immediately in such toxicological emergencies, often without the benefit of full and thorough clinical information on the patient, it is particularly important that any drug or therapeutic substance administered to the patient be substantially free of adverse effects. Sorbents, which when introduced into the patient's gastrointestinal tract resist decomposition and adsorb the ingested toxins until eventual excretion by the patient, have been employed for decontamination. Of those sorbents, activated charcoal has emerged as the decontaminant of choice. Its administration to poisoning victims has now surpassed the administration of syrup of ipecac as the single most important general toxicological treatment measure.
Activated charcoal is a fine, black, powdery substance which is tasteless, odorless, and non-toxic. Activated charcoal is generally formed by oxidation (activation) of combustion residue derived from a controlled process performed on wood, peat, or other organic material producing a substance composed of extremely porous particles with extraordinarily high internal surface area, typically ranging between about 900 m2/g and about 2000 m2/g. Activated charcoal exhibits great adsorptivity and thus has proven to be quite effective as a decontaminant when introduced in sufficient quantities in a timely manner into the gastrointestinal tract of a poisoning victim. The chief mechanism of action of activated charcoal is by its direct binding with toxins in the gastrointestinal tract. A secondary mechanism, called intestinal dialysis, occurs when activated charcoal in the intestine is able to remove toxins from blood within the intestinal blood vessels. Toxins bound to the activated charcoal in the gastrointestinal tract are excreted in the stool.
Activated charcoal is currently available in several forms to be orally administered to individuals who have ingested a toxin. In the most widely used form, activated charcoal is contained in a suspension such as commercially available ACTIDOSE AQUA and CHARCOAID 2000. Activated charcoal is also available extensively in Europe and to a more limited extent in the United States simply in its powdered or granulated form for mixture within a drinkable liquid prior to ingestion. In yet another form, activated charcoal is contained in tablets or capsules for the treatment of gas and upset stomach. Use of these tablets or capsules for decontamination in toxicological treatment however is not readily feasible due to the large number that would be required and the impracticality of administration to children.
In whatever form activated charcoal is delivered to the gastrointestinal tract (e.g., suspended in a liquid, compressed within a tablet or capsule), the activated charcoal is likely to have beneficial effects if the necessary amount can be expeditiously delivered to the gastrointestinal tract of the victim. Therein lies the single greatest obstacle to optimal utilization of activated charcoal as a decontaminant in toxicological treatment. Except for the tablet or capsule form, which presents its own obstacles to ingestion, the antidotal substances are extremely unpalatable. Liquid antidotal suspensions of activated charcoal, for instance, form a black gritty liquid bearing a striking resemblance to old engine crank case oil, which is off-putting to children and adults alike.
Whereas to an adult poisoning victim, the noxiousness of an activated charcoal-containing antidote may simply represent an unpleasant consequence that must be tolerated to avoid the far greater consequences of the poisoning, it would hardly be such a trivial matter to a young child victim. Children will simply refuse activated charcoal in a form that is not appealing to them.
Aspiration is the most serious risk of activated charcoal administration and, although rare, can be life-threatening. It usually occurs in the patient who is vomiting, is uncooperative, or has altered mental status and is most often associated with the placement of a nasogastric or orogastric tube in the absence of airway protection.
In cases where activated charcoal must be administered to an uncooperative patient, there is no choice but to introduce it through a nasogastric or orogastric tube. This procedure often requires physically restraining the patient. It also carries the risk of trauma to the mouth, pharynx, esophagus and stomach. Inadvertent placement into the tracheo-bronchial tree can result not only in trauma to these areas, but in massive charcoal aspiration which can be fatal.
Efforts have been made to render the currently available forms of activated charcoal more palatable, but those efforts have at best yielded only products that may be somewhat less noxious but certainly not palatable especially to young children. Those efforts at times have led to the introduction of substances or components, which may actually diminish the adsorptivity of the activated charcoal, thereby undermining the singular central function of the antidote.
There is a continued need for an antidotal product containing ample quantities of activated charcoal, which is palatable and in which the adsorptivity of the activated charcoal is not diminished in any substantial measure. In addition, the product should be familiar in form and taste to a young child.